Curious multisection identities by index factorization

This manuscript introduces a general multisection identity expressed equivalently in terms of infinite double products and/or infinite double series, from which several new product or summation identities involving special functions including Gamma, hyperbolic trigonometric, polygamma, zeta and Jacobi theta functions, are derived. It is shown that a parameterized version of this multisection identity exists, a specialization of which coincides with the standard multisection identity.